瞬间动用法和两端压力平衡法测定最小启动压力梯度,耗时都较长,且数据准确度不高."压差-流量法"测试拟启动压力梯度,在定围压模式下的测试结果会偏大.基于上述分析,设计出了一体化实验流程,并制定出"非稳态动用-压力平衡法",优选出"压差-流量法"最佳实现方式.该流程通过采用精密设备来保证测试数据的精确度,且适用各种渗透率范围岩心的测试.通过将本方法应用于吐哈油田岩心测试,测定结果符合预期,可以将该方法推广到实验室测量中.%Instantaneous threshold method and dual-ends pressure balance method are commonly used to test minimum threshold pressure gradient,but they are time-consuming and hard to ensure the accuracy of measurement data.The test results of pseudo threshold pressure may be slightly higher by using method of"differential pressure-flow" under constant confining pressure.Based on the above considerations,a set of integrated experiment process is designed,and the method of unsteady threshold-pressure balance is formulated.Also the way to implement the method of "differential pressure-flow" is optimized.The accuracy of the test results is ensured by using precise equipments in the experiment process,and the process is suitable for a wide range of core permeability test of threshold pressure gradient.Test results meet the ex-pectation when this method is applied to well cores in Tuha oilfields,and this method can become a common measurement in the lab.
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